Grade 8 – Perfection – extremely slow even growth, the widest growth ring within the template area about 1mm. Straight grain and even colour. Best possible quartering and the minimum possible run-out (short grain). The wood will be stiff with a high pitched tap tone.
Grade 7 – Near perfection – very slow growth, the widest growth ring within the template area about 2mm. Straight grain. Very well quartered with minimal run-out ( short grain ). Stiff boards with high pitched tap tone. Minimal colour variation may be present.
Grade 6+ – Superior – slow growth, the widest growth ring within the template area about 2.5mm. Well quartered with minimal run-out (short grain). Stiff with a high pitched tap tone. Infrequent inclusion of other quality issues, e.g. minor flame, slight colour variation etc. Most makers would still regard this grade suitable for high end work.
Grade 6 – Fine quality – slow to medium growth, the widest growth ring within the template area about 3mm. Quartering and run-out should still be to a good standard and a good tap tone will still be present. Some inclusion of other quality issues, e.g. minor flame, slight colour variation etc. Ideal for less expensive instruments and student work.
Short grain, poor quartering, fungal discolouration, resin pockets, unsightly colour variation etc. are avoided in the selection process but if and when they are present result in the board being demoted a grade or two.